This invention relates to the field of saw chain. The performance of a saw chain depends on various factors. Most important is cutting speed. A second very important factor in saw chain performance is the ability of the chain to retain a sharp cutting edge for a prolonged period, generally denominated the "stay sharp life" of the chain. Smoothness of operation constitutes a third crucial factor. Other factors include resistance to stretch, resistance to uneven or excessive bottom wear, and the avoidance of the dangerous kickback phenomenon.
The typical saw chain of the prior art more or less follows the configuration illustrated in Cox, U.S. Pat. No. 2,508,784 which comprises an alternating series of center links and pairs of side links pivotally joined to form a chain with certain of the side links being cutter links comprising an integral, upstanding cutter tooth formed at the rear of the link and an integral, upstanding depth gauge at the front of the link. Prior to the present invention, this general configuration was widely held in the art to give the best overall saw chain performance. The ability of a chain to make ripping cuts as well as cross cuts is also an important factor in saw chain performance. There is a continuing need to provide saw chains which give improved performance as to all of the foregoing aspects of chain quality.